Film folding mechanism for a film rewinder

ABSTRACT

Smooth rolls of high cling plastic films, such as polyethylene or vinyl chloride/vinylidene chloride copolymer films, are provided with an easily started leading end by directing a timed air blast against the trailing end of plastic web being wound on a core as the trailing end passes from a supporting roll on a film rewind machine to the core. The air blast is directed to a point at the center or at the edges of the web whereby the trailing end of the web is caused to fold in such a manner to provide a leading end on a wound roll whereby unwinding can be easily started.

United States'Patent Ramsey 1 3,689,001 Sept. 5, 1972 [54] FILM FOLDING MECHANISM FOR A FILM REWINDER [72] Inventor: Ronald L. Ramsey, 1806 Burlington,

Midland, Mich. 48640 [22] Filed: Oct. 21, 1970 [21] Appl. No.: 82,577

52 US. Cl. ..242/56 A [51] Int. Cl ..B65h l9/20,-B65h 19/26 [58] Field of Search ..242/56 R; 242/56 A [56] References Cited UNITED STATES PATENTS 3,089,660 5/ 1963 Bicane ..242/56 A 3,091 ,41 l 5/1963 Heams ..242/56 A 3,342,434 9/1967 Conrad, Jr. ..242/56 A X 3,411,732 11/1968 Ebneter ..242/56 A 3,472,462 10/ 1969 Young ..242/56 R 3,529,785 9/1970 Mistelle ..242/56 A 3,539,125 ll/l970 Patrikssona ..242/56R Primary Examiner-Stanley N. Gilreath Assistant ExaminerMilton Gerstein Attorney-Griswold & Burdick, R. G. Waterman, L. J. Dankert and M. S. Jenkins [57] ABSTRACT Smooth rolls of high cling plastic films, such as polyethylene or vinyl chloride/vinylidene chloride copolymer films, are provided with an easily started leading end by directing a timed air blast against the trailing end of plastic web being wound on a core as the trailing end passes from a supporting roll on a film rewind machine to the core. The air blast is directed to a point at the center or at the edges of the web whereby the trailing end of the web is caused to fold in such a manner to provide a leading end on a wound roll whereby unwinding can be easily started.

3Claims,l0DrawingFigures P'A'IENTEB 5 W m 1 33891001 INVENTOR. Rona/0Q. Ramaey BY M6MM HTTORIVEKS' FILM FOLDING MECHANISM FOR A FILM REWINDER BACKGROUND OF THE INVENTION This invention relates to a film rewind machine and more particularly to a method and means for providing an easily started leading end on the wound plastic film roll.

Standard film rewind machines generally include a reel having multiple spindles arranged for receiving unwound cores, winding said cores, and releasing the wound cores, which operations are automatically performed in a sequential manner. A cut-off means, such as a rotatable knife or a hot wire or a saw-tooth cutter as disclosed in US. Pat. No. 3,091,411, is arranged for severing the film after a core has been wound, while a film transferring means such as transfer pads or a stripper blade is arranged for lifting the end of the severed film from a metering roll and directing the film onto a new core for winding thereon. In many conventional apparatus, a rider roll is positioned so as to flatten the film as it is wound onto the core thereby preventing the formation of wrinkles in the wound roll of film.

In the case of high cling films, particularly the polyethylene films and films of vinylidene chloride/acrylonitrile copolymers and of vinylidene chloride/vinyl chloride copolymers, the relatively high tension on the web being wound on the core causes the severed end or trailing end of the web leaving the metering roll to adhere to or cling to the film roll. As a result, the film is very difficult to start from the film roll, particularly after being packaged and stored for a period of time. With film rolls provided by some rewind machines, particularly those machines employing a serrated knife as the film severing mechanism, the film is often easily torn as it is initially unrolled from the wound film roll.

Heretofore, such problems have been partially overcome by the application of an antiblocking agent to the severed end or trailing end of the web or by marking such trailing end in some way. Such techniques are generally undesirable as they are difficult to employ in high speed rewinding operations which are characteristic in plastic film production and often the film still tears upon removal from the wound film roll.

Therefore it would be highly desirable to provide a mechanism for altering the end of the web in such a manner as to provide an easily started leading edge from the wound plastic film roll.

SUMMARY OF THEINVENTION The present invention is an improved film rewind machine and method of rewinding which provide a simple and satisfactory solution to the problems encountered when attempting to provide an easily started leading end on a wound roll of plastic cling film. The improvement of the invention comprises an air jet arranged to direct an air blast to a point or points on the surface of the trailing end of the web as the trailing end passes from a metering roll on a conventional film rewind machine or similar film winding apparatus to the wound film roll. The blast is directed to a point or points on the web surface to cause the trailing end of the web to fold thereby forming an end on the wound film roll which provides a leading end whereby unwinding can be easily started.

- In another aspect, the invention is a method for folding the trailing end of a plastic web being wound on a core to form a roll of film, whereby unwinding from the roll can be easily started. The method of the invention comprises directing a blast of air from an air jet to a point on the surface of the web as the trailing end of the web passes from a metering roll or similar supporting roll to the wound roll of film. Advantageously, the metering roll or similar supporting roll is proximate to the wound film roll.

The practice of the present invention is particularly advantageous in the production of rolls of wound film for household and industrial use. The invention is conveniently practiced using all conventional 'high speed film rewind machines.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a film folding mechanism as it is incorporated in a film rewind machine.

FIG. 2 is the same but illustrating a different stage of operation.

FIG. 3 is a schematic illustration of a film rewinder employing a rider roll.

FIG. 3a is a perspective view of an air jet manifold which can serve as a plurality of jetson a multicore rewind machine.

FIG. 4 is an isometric view of the air jet as the blast of air from the jet is applied to the surface of the web at a point near the center of the web.

FIG. 4a is a fragmentary, side elevation view of the air jet and web depicted in FIG. 4.

FIG. 4b is an isometric view of the air jet and roll of the web after the blast of air has been applied in the manner indicated in FIG. 4 thereby causing the edges of the web to fold in a direction toward the roll FIG. 5 is an isometric view of the air jet as blasts of air from the jet is applied to the surface of the web at points near the edges of the web.

FIG. 5a is an isometric view of the air jet and roll of the web after the blast of air has been applied in the manner shown in FIG. 5 thereby causing the edges of the web to fold in the direction away from the roll FIG. 6 is a schematic view of an air jet mechanism in accordance with a preferred embodiment of the inventron.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, the numeral 3 identifies a web or a film of high cling plastic material, which is being supplied under tension from a web source 5 and is directed over a metering roll 14 for winding on a core 30 supported by a reel assembly '20. The reel assembly 20 is arranged for rotary movement about a mandrel l6 and is provided with a plurality of spindles 21 adapted for receiving an unwound core 31 from a supply of unwound cores 32, moving the unwound core 31 into an ejecting position, and moving the wound core 30 into an ejecting position, which operations are performed in intermittent and sequential manner. A web severing means 6 such as a knife, a serrated blade or a hot wire as described in U.S. Pat. No. 3,091,41 1 is located adjacent to the metering roll 14 or at some point between the metering roll 14 and the wound core 30. The web severing means 6 is activated in a similar intermittent and sequential manner such that the web 3 is severed at a time when the winding cycle for a given wound core 30 is nearly completed.

Referring particularly to FIGS. 1 and 2, in using the rewind machine depicted therein for rewinding certain high cling plastic materials on paper cores, such as for household use, the web 3 is severed by a rotatable knife 6. Winding of the web 3 on the wound core 30 continues until the severed end of the web 3 passes from the metering roll 14 to the wound core 30. As the severed (trailing) end of the web 3 travels from the metering roll 14 to the wound core 30, a blast of air from an air jet 36 is directed to the surface of the web 3. Preferably the air blast is directed to the center of the web as depicted in FIG. 4 or to each of the two edges of the web 3 from two air jets as shown in FIG. 5. In each instance the air blast flows in a direction generally perpendicular to the plane of web as depicted in FIG. 40. As a result of the air blast or blasts, the severed end of the web 3 is folded depicted in FIGS. 4b and 5a thereby providing an easily started leading end for removal of the film from the roll wound on the core.

Referring now to FIG. 3, there is depicted a film rewind machine of particular interest in the practice of the present invention. Accordingly, the web 3 is being supplied from a mill roll 5a and is directed over a series of dancer rolls 4. The web 3 is then passed between a steel draw roll and a rubber draw roll 11 and directed under a slitter bed roll 13 such that a razor blade slitter 12 slits the web 3 in longitudinal manner to form a plurality of web strips. The web strips are then directed over the metering roll 14 to a plurality of wound cores 30. A rider roll 17 when in closed position as indicated in FIG. 3 bears on the wound cores 30 along their length so that the web strips being wound thereon are wrapped in a snug and smooth manner on the wound cores 30 thereby preventing the formation of wrinkles in the web strips on the wound cores 30. The web strips are severed with a chopper roll 6a as the blade 8 engages a spaced pair of knives 41 and 42 which are slidably mounted in the metering roll 14 such that the knives 41 and 42 move outwardly from the surface of metering roll 14 when the web strips are severed. The knife 41 has a serrated edge and the knife 42 has a smooth edge.

As the severed ends of the web strips travel from the metering roll 14 to the wound cores 30, blasts of air from anair jet manifold 36a, depicted in more detail in FIG. 3a, are directed to points on the surfaces of the web strips. The severed ends of the web strips are thereby folded. The ,rider roll 17 presses the folded severed ends against the wound cores 30, thereby providing the wound cores 30 with easily started leading ends which do not tear upon removal of the film from the cores.

As the severed ends of the web strips are pressed against the wound cores 30, the rider roll 17 disengages the wound cores 30 by moving away from the reel assembly 20 thereby providing clearance for the wound cores 30 to be rotated out of winding position and unwound cores 31 to be rotated into winding position.

Simultaneous with severing of the web strips, a series of transfer pins 43 located adjacent to the knives 41 and 42 and also slidably mounted in the metering roll 14 move outwardly from the surface of the metering roll 14 to catch the leading ends of the web strips which are to be transferred to unwound cores 31 as they are rotated into position for winding. Transfer of the leading ends of the severed web strips from the metering roll 14 to unwound cores 31 in winding position is effected by moving transfer pads 44 located adjacent to the transfer pins 43 and slidably mounted in the metering roll 14 outwardly from the surface of the metering roll 14 such that the leading ends of the severed web strips contact the unwound cores 31 now which have been rotated into winding position. The web strips are preferably held in contact with the unwound cores 31 by glue which has been previously applied to the unwound cores 31. The winding of the web strips is then started and the rider roll 17 is moved back into position to engage the now winding cores. Such winding will continue until the cores are wound in the amount desired, after which the web strips are again severed and the operation of the air jet manifold 36a is repeated in automatic manner.

In preferred embodiments, it is desirable that the air jet be placed at a point not more than about 1 foot from the web surface to be contacted with the air blast. Accordingly, an air jet maybe placed in contact with the web surface or at some distance up to about a foot away from the web surface, especially at distances from about 1 to about 4 inches from the web surface. Although the drawings indicate that the air jet can be located in a position above the web, the air jet is also suitably located in a position below the web in many conventional film rewind machines. In order to obtain the best results, it is generally desirable to position the air jet such that an air blast therefrom flows in a direction generally perpendicular to the plane of the web as it passes from the metering roll to the wound core. The period of the air blast depends primarily on the speed of the moving web as it passes from the metering roll to the wound core, generally such speeds range from about 300 to about 2000 feet/minute. At such speeds, the period of the air blast is from about 1/90 to about 2 seconds, preferably between about l/30 to about one-half second, with webs moving at higher speeds requiring the shorter periods.

In the description of this invention, an air jet refers to a member having an orifice or plurality of orifices through which substantial amounts of air can be forced in the relatively short periods mentioned above. Generally, the sizes of such orifices vary from about 0.0078 to about 0.250 inch in diameter, preferably from about 0.0l56 to about 0.0625 inch.

As indicated in FIG. 6, the air jet 36 is served by an air hose 37 or similar such conduit which hose 37 is connected to a valve 39 which controls the flow of air through the airjet. A valve 39 is operated by an opening and closing means 40 which is synchronized with severing of the web 3 and is caused to flow just prior to, 'or simulteneous with, the removal of the plastic web from roll 14. To accomplish properly timed opening and closing of the valve 39, the valve operating means 40 is advantageously activated just after the web 3 is severed. A suitable valve operating means comprises an electrical signaling device 46 such as a solenoid which receives an electric impulse as the web 3 is severed and activates a cam 47 or similar valve opening mechanism which in turn opens the valve 39. In practice the cam or similar valve opening mechanism is set such that there is a slight delay in time between the reception of the signal from the electrical signaling device and the time at which the cam or similar valve opening mechanism causes the valve to be in the fully opened position. This delay approximately corresponds to the time it takes for the severed (trailing) end of the web to pass from the severing mechanism, e.g., rotary knife or hot wire, to the point at which the trailing or severed edge of the web leaves the metering roll 14. In order to supply an adequate amount of air to the air jet 36, it is desirable that the valve means be connected to an air reservoir 48, which is connected to a clean air source 49, preferably regulated at least 40 lbs. per square inch gauge of air pressure. In the practice of this invention wherein the plurality of cores are wound simultaneously, multiple air blasts are supplied by an air jet manifold 360 having a plurality of orifices. The air jet manifold 36a is similarly connected by a serving hose 37.

The present invention is advantageously practiced in the winding of plastic webs having a thickness from about 0.3 to about 2 mils and width from about 9 to about inches. The present invention is most advantageously practiced in the winding of high cling plastic web of polymers such as the polyamonoolefins such as polyethylene, polypropylene, poly(isobutene); homopolymers' and copolymers of halogencontaining a-monoolefins such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride/vinylidene chloride copolymers, vinylidene chloride/acrylonitrile copolymer; polymers of monovinylidene, carbocyclic monomers such as polystyrene, styrene/butadiene copolymer, styrene/acrylonitrile copolymer and styrenelbutadiene/acrylonitrile copolymer. The foregoing polymers are only illustrative and should not be construed as limiting the scope of the invention.

The method and means of the invention provides a simple means for folding thin, limp, high cling film which is being wound on a high speed film rewind machine. Accordingly an easily started leading edge is provided on the wound core.

The foregoing description has been given in detail without thought of limitation since the inventive principles involved are capable of assuming other forms without departing from the spirit of the invention or the scope of the following claims. For example, the present invention can be utilized in film winding machines which do not employ a web severing mechanism in which case the air jet is activated at the time the trailing end of the web passes from a metering roll or similar supporting roll to the roll of film being wound. Generally the metering roll or similar roll is proximate, e.g., from about 1 to about 12 inches, to the roll of film being wound (wound core) at the time the air jet is activated.

WHAT IS CLAIMED IS:

1. In a film winding machine having a supporting roll over which a web of thin, limp, high cling plastic moves under tension from a web source to a core for winding thereon, said core being proximate to said supporting roll; the improvement which comprises an air jet arranged between the core and the supporting roll, said jet being positioned to provide an air blast directed to a point on the surfac e of e web as the web passes fro he supporting rol to e core, and means to supp y compressed air to the air jet for ejection therefrom in order to form said blast of air directed to a point on the surface of the web as the trailing end of the web passes from the supporting roll to the core, said blast of air being arranged to flow in a direction generally perpendicular to the plane of the web whereby the trailing end of the web is folded to provide an easily started leading end for subsequently unwinding the web from the resulting wound core.

2. In a film rewind machine having a rotatable reel for supporting a plurality of cores for winding a web of thin, limp, high cling plastic selectively on said cores, a metering roll over which the web moves under tension from a web source to the reel, said reel being proximate to the metering roll, and a severing means proximate to the metering roll for severing the web to provide a trailing severed end of the web which travels from the metering roll to a wound core; the improvement which comprises an air jet arranged between the reel and the metering roll, said jet being positioned to provide an air blast directed to a point on the surface of the web as the web passes from the metering roll to the wound core, and means to supply compressed air to the air jet for ejection from said jet at timed interval in order to form said-blast of air directed to a point on the surface of the web as the severed end of said web passes from the metering roll to the wound core, said air blast being arranged to flow in a direction generally perpendicular to the plane of the web whereby the severed end of said web is folded to provide an easily started leading end for subsequently unwinding the web from the wound core.

3. A method for folding the trailing end of a web of thin, limp, high cling plastic being wound on a core to form a wound film roll, said web moving under tension from a web source over a supporting roll to the core, which method comprises directing a blast of air from an air jet to a point on the surface of web as the trailing end of the web passes from the supporting roll to the core, said blast of air being arranged to flow in a direction generally perpendicular to the plane of the web whereby the trailing end of the web is folded to provide an easily started leading end for subsequently unwinding the web from the resulting wound core.

* g;;g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,689,001 Dated S pt 5; 97

Inventor(s) Ronald L, Ramsey It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F- Column 2, line 60, delete the words "an ejecting" and insert in their place the words --a winding",

Signed and sealed this 6th day of March 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. 7 ROBERT GOT-TSCHALK Attesting Officer Commissioner of Patents 

2. In a film rewind machine having a rotatable reel for supporting a plurality of cores for winding a web of thin, limp, high cling plastic selectively on said cores, a metering roll over which the web moves under tension from a web source to the reel, said reel being proximate to the metering roll, and a severing means proximate to the metering roll for severing the web to provide a trailing severed end of the web which travels from the metering roll to a wound core; the improvement which comprises an air jet arranged between the reel and the metering roll, said jet being positioned to provide an air blast directed to a point on the surface of the web as the web passes from the metering roll to the wound core, and means to supply compressed air to the air jet for ejection from said jet at timed interval in order to form said blast of air directed to a point on the surface of the web as the severed end of said web passes from the metering roll to the wound core, said air blast being arranged to flow in a direction generally perpendicular to the plane of the web whereby the severed end of said web is folded to provide an easily started leading end for subsequently unwinding the web from the wound core.
 3. A method for folding the trailing end of a web of thin, limp, high cling plastic being wound on a core to form a wound film roll, said web moving under tension from a web source over a supporting roll to the core, which method comprises directing a blast of air from an air jet to a point on the surface of web as The trailing end of the web passes from the supporting roll to the core, said blast of air being arranged to flow in a direction generally perpendicular to the plane of the web whereby the trailing end of the web is folded to provide an easily started leading end for subsequently unwinding the web from the resulting wound core. 